Parasitic infections affect a vast number of people around the world.
Schistosomiasis is a known example of tropical parasitic disease. Since the past decade,
an increasing effort has been made towards its control. There are two main chemical
interventions employed to cut off the schistosomiasis life-cycle. The first one consists of
therapy, to treat infected individuals. The second uses molluscicidal compounds to
control the population of the vector snails. This latter strategy has been considered as
one of the best preventive actions, since it eliminates the parasites before they can reach
human hosts. Towards this end, synthetic molluscicide, niclosamide, has proved to have
efficient activity against schistosomiasis. Nevertheless, undesirable side effects
associated with this compound, such as toxicity to non-target organisms in the aquatic
environment, encouraged the search for new molluscicidal compounds. Although
synthetic drugs often display higher molluscicidal activity than natural products, their
lack of selectivity towards nocive snails, as well as difficult biodegradation, cause
severe burdens on the environment. This problem has caused criticism on the use of the
currently available synthetic molluscicides and turned the interest of a part of the
scientific community to the investigation of new compounds, including natural
substances. In fact, the dilemma between synthetic and natural products is not yet
settled, and it still remains a challenge to find an effective and eco-friendly substance to
combat the snails selectively. The focus of this chapter is to present an overview of
recent studies on synthetic compounds and natural products with molluscicidal activity.
Keywords: Schistosomiasis, snail control, molluscicidal activity, synthetic
compounds, natural products.